He also worked as assistant director on the television drama Getting Up and Going Home (1992), the horror film The Hidden II (1993, starring Raphael Sbarge), the crime thriller Night of the Running Man (1995, with assistant directors Rosemary C. Cremona and Nedra Rosemond), the romance A Walk in the Clouds (1995), the action film Virtual Combat (1995), the television thriller Eye of the Stalker (1995, directed by Reza Badiyi), the fantasy thriller The Crow: City of Angels (1996, with second unit director Doug Coleman), the comedy My Fellow Americans (1996), the crime thriller Retroactive (1997), the short drama Condemned (2002), the short film Wishing Time (2003, with Seymour Cassel), the sport comedy Soccer Dog: European Cup (2004), the comedy Alice Upside Down (2007), the comedy The Kings of Appletown (2009), the crime comedy Venus & Vegas (2010), and the thriller Level 26: Dark Revelations (2011).

In addition to his work as director, Dempsey was an associate producer on the horror thriller The Oakley Seven (2006) and the crime comedy Venus & Vegas (2010) and a line producer on the short science fiction film F*ck You Pay Me! (2007). He also worked as production supervisor on the crime drama Unknown (2006), the drama Dirty Girl (2010), the drama Sound of My Voice (2011), and the drama California Solo (2012).